1. Field of Invention
The present invention relates to cleaning and restoring solutions for CDs. In particular, it relates to a single application rub-on, rub-off combination restorer, cleaner and waxing solution particularly suited for CDs and DVDs.
2. Description of Related Art
Cleaning and waxing solutions for CDs and DVDs are known. A typical CD is a layered piece of injection molded clear polycarbonate plastic. During manufacturing, the clear polycarbonate plastic is impressed with microscopic bumps (ridges and lands) arranged as a single continuous, extremely long spiral track of data circling from the inside of the disc to the outside. The height between the ridges and lands is such that the difference in height between the two is exactly a quarter of a wavelength of the laser beam light. When one half the laser light is reflected from the upper ridge, and the other half hits the lower land surface the resultant reflected light is out of phase and cancels one another out at the ridge/land junction. Once the clear piece of polycarbonate is formed, a thin, reflective aluminum layer is applied covering the bumps. A thin acrylic layer is then sprayed over the aluminum to protect it, and a label is then printed onto the acrylic.
To read the CD, it is optically scanned with a laser light directed through the clear polycarbonate plastic onto the bumps. The refracted laser light is then read by a photo-electric cell and converted into a series of electrical pulses forming digital signals dependent upon whether the laser strikes a “ridge/land” junction, producing a weak reflection, or a “land” or “ridge” producing a stronger signal. Thus the photoelectrical cell receives a series of light pulses corresponding to the length of the ridges and lands in the disc. These light pulses are then converted into binary “digital” data substituting an “O” for a weak signal from a ridge/land junction and a “1” for an in-focus signal from a “ridge” or a “land”. A digital to analogue converter then converts the series of pulses (binary coding) into a waveform that is processed for amplification.
Many CD players use three-beam scanning for correct tracking. The three beams come from one laser. A polarized prism projects three spots of light on the track. It shines the middle one exactly on the track, and the two other “control” beams generate a signal to correct the laser beam immediately, should it deflect from the middle track.
The refractive tolerances of a typical CD are thus extremely critical as they hold about 2 MB of data on the spiral data track. This data track is approximately 0.5 microns wide, with 1.6 microns separated one track from the next and the bumps are even smaller so they must be handled and treated with care.
The CD is a plastic disc I 0.2 mm thick and 12 cm in diameter, with a silver-coated surface that reflects laser light. The maximum playing time for music recorded on compact disc is 74 minutes. The CD has several layers. First, to protect the 8 trillion microscopically small pits against dirt and damage, the CD has a plastic protective layer. On the top of this layer the label is printed. Then there is the reflecting aluminum coating which contains the ridges. Finally, the disc has a transparent carrier through which the actual reading of the disc takes place. This plastic forms a part of the optical system. Mechanically, the CD is less vulnerable than the analogue record, but that does not mean that it must not be treated with care. The protective layer on the label side is very thin: only 0.002 mm. Careless treatment or granular dust can cause small scratches or hair cracks, enabling the air to penetrate the evaporated aluminum coating. This coating then starts oxidizing immediately at that spot. If the CD is played extensively, it may be advisable to protect the label side with a special protective foil, which is commonly available in shops. A CD must never be bent, so care should be taken when removing it from the jewel case. Even slight bending causes stress fractures. The aluminum then becomes deformed, causing some ridges to be blocked. As a consequence, error correction always has to be applied in that area, affecting the final sound.
The reflecting side of the CD is the side that is read. People tend to set the CD down with the reflecting side up. But the more vulnerable side is not the reflecting side but the label side. On the label side, the reflecting layer with its ridges has been evaporated. The sensitive layer on the reflecting side has been protected better than the one on the label side. It is therefore better to store CDs with the reflecting side down. It is best to store the CD back in the jewel case, where it is safely held by its inside edge. Never write on the label side, even with a felt tipped pen. The ink may penetrate the thin protective coating and affect the aluminum layer. If a smear, however small, remains on the CD, much in formation is lost.
CDs are easily scratched, and should never be cleaned with just any cloth. CDs should be cleaned radially: not along the grooves, but at right angles to the direction of the grooves. If a smear, however small, should remain on the CD, running along the direction of the grooves, much information would be lost. It is advisable to use special CD cleaner that operates with a rotating brush at right angles to the direction of the grooves.
To repair the surface reflecting coverings of a damaged CD or DVD, the patents fall in two categories: a metal polishing grinder approach to repair the CD surface of the optical storage medium, see Krieg et al, U.S. Pat. No. 6,261,159 B1, and a coating application repair method of the CD surface, see Howell, U.S. Pat. No. 5,650,001 using silicones instead of wax to fill in surface scratches and improve the temperature range of the treated disc. A CD Repair Kit article from the internet discusses tests of a number of products and methods (Memorex, Maxell, Disc-Saver, Crystal-Disc, Acetone, Toothpaste, Brasso Metal Polish, Rubbing Compound and Comet Cleanser) and found that Brasso metal polish with a mild siliceous polishing powder suspended in ammonium soap jelly and dispersed in Stoddard Solvents is rated as the best product so far (note multiple applications improved results).
Cited for general interest are various waxes and paint restorers: Denissenko et al, U.S. Pat. No. 3,992,335 discloses a self-shining floor care composition capable of rendering the surface of a substrate such as a wooden parquet floor shiny, without prior wax stripping and without subsequent polishing. It provides an anhydrous solution comprising of at least six and preferably seven constituents:                1. a solid, film-forming macromolecular compound,        2. a hard resin,        3. a liquid plasticizer,        4. a solid plasticizer,        5. a solvent mixture consisting of at least one lower alkanol and        6. a liquid co-solvent, and        7. an optional silicone oil.Dinissenko et al is not adapted to restore oxidized painted surfaces of automobiles and other items before application. It therefore requires a paint restoration step before application.        
Aberg, U.S. Pat. No. 4,952,248 discloses a method and apparatus for dry cleaning and shining of vehicles, especially motor vehicles and other waxable surfaces. The method includes the steps of applying a solution of ammonia, water and alcohol to the surface of the vehicle or other waxable surface, toweling the surface to spread the applied solution, partially remove and evaporate it to allow the alcohol to liquefy or soften the wax on the surface preparatory to finish polishing. It provides a chemical means for leveling the wax on the surface replacing mechanical buffing. The preferred solution includes 1½ ounces of commercially available ammonia preparation, 10 ounces of water and 4 ounces of isopropyl alcohol. Alternatively the solution includes 1½ ounces of ammonia with 6 ounces of water and 4 ounces of isopropyl alcohol (70% by volume), or mixtures within these ranges. Aberg also requires a prior paint restoration step to remove paint oxidation before applying a waxing mixture
Conrad et al., U.S. Pat. No. 6,551,974 discloses a composition and method for use in imparting or maintaining a glossy or shiny finish on a hard surface. In one embodiment, the composition comprises a base polish component or components, and at least one poly [oxyalkyline] ammonium cationic surfactant, which provides an improved gloss or shine imparting properties. It is then applied to the hard surface. The poly [oxyalkyline] ammonium cationic surfactant comprises in the range of about 0.01 to about 10 wt. %, more preferably in the range of about 0.05 to about 5 wt. % and more preferably in the range of about 0.1 to about 1 wt. % of total composition. This composition preferably includes polishing agent abrasives to remove contaminants. These abrasives reduce the paint surface thickness and require extensive buffing for removal.
Other paint cleaning and waxing solutions require separate multiple sequential steps of the application and removal of paint restorers, and waxes.
The present invention described below provides a combination mild abrasive hard wax restorer with built in polish operating over an extensive temperature range, which is a significant improvement over these methods and apparatus described above as it doesn't require multiple coats or require a grinding apparatus.